Relations of Anemia With the All-Cause Mortality and Cardiovascular Mortality in General Population: A Meta-Analysis

Background: Anemia may be an independent risk factor of death. Therefore, the current meta-analysis aimed to explore the relationship of anemia with all-cause mortality (ACM) and cardiovascular mortality (CVM) to provide evidence-based medical facts. Methods: Three major electronic databases, the National Library of Medicine of the USA (PubMed), Cochrane Library and Embase, were searched from inception to October 2018. Relevant studies were screened in strict accordance with the inclusion and exclusion criteria, and the pooled hazard ratios (HRs) together with the 95% confidence intervals (CIs) were performed to assess the statistically significant difference of anemia compared with ACM and CVM. Results: A total of 15 related studies were included. Our results suggested that among the mixed population regardless of sex, age and cardiovascular diseases (CVD), the ACM and CVM of anemia patients were increased, with the HRs and 95% CIs of 1.41 (1.33, 1.50) and 1.33 (1.23, 1.45), respectively. Meanwhile, the ACM of anemia patients with the mean age of over 65 or below 65 years was increased irrespective of sex and CVD, with the HRs and 95% CIs of 1.43 (1.26, 1.61) and 1.41 (1.32, 1.50), separately. Moreover, the risks of ACM were increased in male, female and mixed sex anemia patients despite age and CVD, with the HRs and 95% CIs of 1.39 (1.29, 1.49), 1.25 (1.20, 1.30) and 1.53 (1.39, 1.68), respectively. All patients with CVD and no CVD were associated with an increased risk of ACM regardless of age and sex, with the HRs and 95% CIs of 1.42 (1.33, 1.51) and 1.38 (1.16, 1.63), respectively. Conclusions: Anemia is a risk factor to predict ACM and CVM among the general population, which is independent of sex, age, and history of CVD.